Lisa Schwartz, MD, and Steven Woloshin, MD, of Dartmouth Medical School's Center for the Evaluative Clinical Sciences, the Veterans Affairs Outcomes Group, White River Junction, Vermont and the Norris Cotton Cancer Center compared how the major US news media covered the potential benefits and harms of mammography versus the prescription drug tamoxifen (trade name Nolvadex) used for the primary prevention of breast cancer. They performed a content analysis of major US news media (top 10 circulation newspapers) and three major television to look at the two weeks of media coverage following three events: National Institutes of Health (NIH) consensus panel not recommending screening mammography for women in their forties, the National Cancer Institute's (NCI) reversal of the panel (advocating mammography) and the dissemination of the results of the randomized trial of tamoxifen for primary prevention.
They found differences in how the media reported on these issues. "Most news stories favored routine use of screening mammography and urged caution about using tamoxifen. Almost all noted the potential harms of each preventive strategy; however, the negative aspects of tamoxifen received greater emphasis. Whereas taking tamoxifen was presented as a difficult decision, having a mammogram was presented as something a woman ought to do," the physicians say. The NIH consensus panel stories were generally enthusiastic about mammography. Most left the reader with the impression that women in their forties should be screened and, in many cases, there was a sense of anger at the panel for the failure to recommend mammography. The NCI reversal stories were almost universally supportive and many expressed relief that the consensus panel had been refuted and their error corrected. These stories were remarkable for the extent to which politicians and advocacy groups were represented and for a new focus--ensuring that mammography would be covered by insurance, note the researchers. In contrast, tamoxifen stories were almost all cautious. Stories all quoted scientists, few advocates and no politicians. Rather than rejecting uncertainty, they accepted it and suggested women needed to weigh risks and benefits themselves.
Two-thirds of the stories quantified the benefit of the strategy, but 60% of these did so using only a relative risk reduction--a format known to exaggerate the perceived importance of the finding (49% reduction without telling the base rate--67 per 10,000 (annual rate). Harm was mentioned in nearly all stories about consensus panel and tamoxifen but in only half of the NCI reversal stories. It had greater emphasis in the tamoxifen stories. Most commonly noted harms were false positive, false negative; few stories mentioned over-diagnosis. 90% of the tamoxifen stories mention the potential harm of uterine cancer, but only 44% mentioned lung or leg clots--the cause of the deaths observed in the trial.
While the difference in the coverage of these distinct approaches to breast cancer prevention may not be surprising, the authors raise two interesting issues. First, do the differences in press coverage reflect different attitudes about de-emphasizing an established medical practice as opposed to publicizing a new one? Since tamoxifen is the first instance of cancer chemoprevention, news stories may have been appropriately cautious about the idea of healthy (although higher risk women) taking a medication. The mammography controversy followed a recommendation to reverse support for an established practice. Another explanation may be the different perceptions about the potential harm of a screening test compared to a medication.
Women concerned with breast cancer may consider a range of approaches to reducing their risk that have received varying levels of publicity. The intense news coverage about mammography for women in their forties and the use of tamoxifen for the primary prevention of breast cancer undoubtedly alerted many women to their existence. Mammography stories generally supported its use, and few questioned basic assumptions about screening, the researchers found. Reporters seemed to allow the scientific content of the debate to be eclipsed by its political and emotional aspects.
In contrast, stories about tamoxifen maintained a more dispassionate, scientific stance; reporters approached tamoxifen cautiously and were willing to question assumptions of benefit. The authors assert that reporters should scrutinize screening tests as critically as they examine drugs. By doing so, they may help the public better appreciate the pros and cons of medical interventions.
Balanced media coverage about the benefits, harms and uncertainties of mammography--or any medical intervention--would help focus the new debate on science rather than emotions or politics, they say.
DMS news is on the web at www.dartmouth.edu/dms/news.